Yes it is and their support knows what you're talking about when you say that you're using your own router. They'll even help you set it up if they see you know what you're doing. Swisscom is a bit different in that respect.
i know that's not very useful to your issue right now.
Check their competitors like init7, gga maur, etc., they're easier to deal with and much cheaper. they top out at 1gbit but I can't think of a use for 10gbit at home. And 10gbit Ethernet is so expensive, so anything faster than a gigabit is wasted anyway.